Field of the Invention
Embodiments of the invention relate to a thermal barrier for use in chambers and chamber components utilized in thermal processes in the manufacture of electronic devices on substrates.
Description of the Related Art
Substrate processing chambers are commonly used in semiconductor manufacturing in order to fabricate electronic devices on a substrate. These chambers include a heater, which is typically in the form of a disk-shaped body, made of ceramic material, and includes a heating element embedded in the disk-shaped body. The heater is used to support the substrate and the heating element is used to heat the substrate to a desired temperature to facilitate an electronic device fabrication process on the substrate, which includes deposition, implantation, or etching. The heaters, and heating elements embedded therein, are typically constructed to apply uniform thermal energy to a substrate receiving surface of the ceramic body, which is typically an upper surface of the disk-shaped body.
Large amounts of energy are applied to the heating element of the heater, and the heat applied to the heating element is generally transferred by radiation, conduction and/or convection to the substrate. However, a great portion of the energy applied to the heating element is lost through a backside of the disk-shaped body (opposite the substrate receiving surface) as well as minor surfaces (sides) of the disk-shaped body. This lost energy is generally radiated from these surfaces to the chamber where the heater is installed. The lost energy from these surfaces may detract from the efficiency of the process by freeing thermal energy that would otherwise be used to heat the substrate. The lost energy may also be absorbed by other chamber components, and some of the chamber components are required to be maintained at a much lower temperature than the temperature of the heater and/or the temperature of the substrate in order to prevent deposition on these chamber components. As a result, the chamber components must be cooled by cooling fluids to remove the thermal energy radiated by the heater. Thus, the conventional heaters provide inefficient use of power that is converted to thermal energy, and heating of peripheral chamber components requires supplemental cooling apparatus and methods to remove this excess heat, both of which contribute to cost of ownership. Further, surfaces of chamber components that are heated by processes performed therein, such as chamber sidewalls, may lose this thermal energy to the surrounding environment. This lost energy further reduces the efficiency of the manufacturing process and may add to cost of ownership.
Therefore, there is a need for a thermal radiation barrier that is applied to chamber components to reduce thermal energy losses.